**4. Conclusions**

We described two numerical models for (1) a heat exchanger design and (2) an indoor airflow control. The fin-and-tube heat exchanger model consists of CFD and a one-dimensional refrigerant circuit model. CFD model simulates airflow velocity and temperature, and refrigerant circuit model calculates refrigerant flow pressure and enthalpy. These two models are coupled using the value of amount of heat transfer between air and refrigerant. The indoor airflow model can simulate indoor airflow temperature and velocity by the room air conditioner airflow control. We verified three simulations and the measured temperature data. The arrival position of the blowing air was found to be consistent between experiments and calculations, but some differences were found in the airflow temperature distribution in the room due to the existence of gaps in the wall.
